I would recommend a new install on different hardware or VM and migrating the roles to the new server.
An in place upgrade of non-R2 2008 to 2012 R2 is not supported, as in the table at:
https://technet.microsoft.com/en-gb/library/dn303416.aspx

The article will show you how you can maintain a simple logfile of all Startup and Shutdown events on Windows servers and desktops with PowerShell. The script can be easily adapted into doing more like gracefully silencing/updating your monitoring s…

New Windows 7 Installations take days for Windows-Updates to show up and install. This can easily be fixed. I have finally decided to write an article because this seems to get asked several times a day lately.
This Article and the Links apply to…

This tutorial will walk an individual through the steps necessary to enable the VMware\Hyper-V licensed feature of Backup Exec 2012. In addition, how to add a VMware server and configure a backup job.
The first step is to acquire the necessary licen…

This tutorial will walk an individual through the steps necessary to join and promote the first Windows Server 2012 domain controller into an Active Directory environment running on Windows Server 2008.
Determine the location of the FSMO roles by lo…